1. Technical Field
The present invention relates to a wheelchair, comprising a frame which supports, on the one hand, the wheels of the wheelchair and, on the other hand, its seat, back rest and, where applicable, its foot rests, the seat, the back rest and, where applicable, also the foot rests being adjustable in relation to one another.
2. Prior Art
There are many types of wheelchairs and they have long been developed so as to be increasingly usable and readily operable for the user sitting in the wheelchair. In general, wheelchairs have most or all of the following components: a seat on which the user sits, a back rest in connection with the seat, handles in connection with the back rest if any person other than the user is to move the wheelchair forwards, foot rests if there is a need for them, and a chassis or a frame which supports the previously mentioned components. All parts are, in most modern wheelchairs, adjustable for an adaptation to suit the user.
There are also numerous variations of modern wheelchairs, for example, the method of propulsion differs between various types of wheelchairs. Certain types of wheelchairs are intended to be propelled forwards by the user, at least from time to time. For this to be possible, two of the wheels are sufficiently large for the user to be able to reach them and revolve them. Wheelchairs which are intended to be propelled only by a person other than the user or with the aid of a drive motor may be provided only with small wheels which cannot be reached by the user. Wheelchairs may also be manufactured with either a fixed or a collapsible frame. The choice of frame type depends on the user's needs, for example if there is a need to transport the wheelchair in a normal private car, where the collapsible variation is often preferable.
Since a user spends much time in the wheelchair, at least if the need for a wheelchair is permanent, the adaptation capability of the wheelchair to the user is of paramount importance. As a result, stress- or wear injuries may be avoided or at least reduced and, moreover, the user may gain maximum benefit from a well-adapted wheelchair. However, one problem in the adjustment of the wheelchair is that if the adjustment of a part of the wheelchair is altered, for example its height, this alteration entails a series of consequential modifications such as alteration of the seat and the foot rests. A further drawback is that a large number of various tools are required in order to carry out these various modifications.
A further serious problem is that also brakes and other safety devices must be adjusted when the basic adjustment of other parts of the wheelchair is altered. If this is not put into effect, the safety function may be disabled and, as a result, the wheelchair may be dangerous to use.
Finally, a complex adjustment entails that temporary alterations to, for example, the height of the wheelchair in order to adapt it to different environments is not carried out. Instead, the user must be content with an imperfectly adapted wheelchair on certain occasions. If, on the other hand, such adjustment had been easier to put into effect the mental resistance to temporary re-adjustments is not as great, and the user may gain maximum benefit from the wheelchair.